A New Genus (Protosciadopityoxylon gen .nov .) of Early Cretaceous Fossil Wood from Liaoning ,China

Anewgenus (Protosciadopityoxylongennov .)ofEarlyCretaceousfossilwoodreportedinthepre sentpaperwasdiscoveredfromLiaoningProvince ,China ,andisnamedasanewspecies :Protosciado pityoxylonliaoningensegen .etsp .nov .Itisdescribedhereandthisgenericname ,adoptedbytheauthors ,is employedforfossilwoodthatisbelievedtobenearlyrelatedtotherecentgenusSciadopitysandthefossil genusSciadopityoxylon .ThenewgenusbearssomesimilaritiestoProtophyllocladoxylon ,Protocircoporoxylon andXenoxylonindifferentgeologicalages ,butitdiffersfromtheminthetypesofcross_fieldpitting .

New Discoveries of Phaeophycean Fossils in the Early Cambrian, Haikou, Kunming,Yunnan, Southwest China

The paper deals with the new phaeophycean fossils in the Early Cambrian from Chengjiang Biota at Ercai Village of Haikou, Kunming, Yunnan, Southwest China. Three new taxa, Punctatiopsis latifolia gen. et sp. nov., P. simplex gen. et sp. nov. and Vendotaenia cf. antiqua Gnilovskaya axe described here in detail. These new findings show that the Chengjiang Biota is high in species diversity of fossil algae and might offer new evidence for a better understanding of the Cambrian explosive biological evolution. The fossil genus described here is found to have a close relationship with the living Punctatia based on similar morphology. The results suggest that the Chengjiang Biota in Haikou area of Kunming was living in an intertidal and subtidal seawater environment.

A New Species of Araucarioxylon Kraus from the Early Early Permian, Nei Mongol, China

A kind of silicified fossil wood with mixed pits on the radial tracheid wall is described. The fossil wood was collected from the top of Taiyuan Formation (early Early Permian) in Wuda Mining District, Nei Mongol. Compared with the Paleozoic fossil woods in the world, it is put into Araucarioxylon Kraus and named as A. laoshidanense sp. nov. Based on the character of possessing mixed pittings (alternate and opposite pittings) on the radial tracheid wall, the fossil wood is believed to be one of the unknown primitive conifers.Diagnosis of the new species: Only secondary xylem preserved and consisting of axial tracheids and rays. Growth ring boundary, resin duct and axial parenchyma absent. One to Four (commonly 2 or 3) seriates of bordered pits (mostly alternate but sometimes opposite) on the radial tracheid wall. One to Four (commonly 1, rarely 2 to 4) Cupressoid pits in each cross_field. Rays usually uniseriate, sometimes partly_ biseriate and 2 to 39 (mainly 3-5) cells high.

Geochronology,geochemistry and Hf isotopic study of Early Carboniferous granodiorites in Taerqi region,central Daxing'anling and its tectonic implication

Zircon U-Pb age,whole rock geochemical and zircon Hf isotopic data are presented for Late Paleozoic granodiorites from the Taerqi region,central Daxing'anling to constrain its petrogenesis and tectonic implication.LA-ICP-MS zircon U-Pb age data indicates that the Late Paleozoic granodiorites were emplaced with age of333.4 ± 2.2 Ma(Early Carboniferous).Geochemically,the granodiorite samples have Si O2= 60.54%-71.40%,Na2 O = 4.04%--4.66%,K2 O = 1.65%--4.27% and Mg O = 0.96%--3.53%,belonging to medium-K to high-K calc-alkaline I-type granites.They are slightly enriched in large ion lithophile elements(e.g.Rb,Th,U and K) and light rare earth elements,and depleted in high field strength elements(e.g.Nb,Ta and Ti),with εHf(t) values of 8.0--11.8 and Hf two-stage model ages of 586-829 Ma.All these geochemical features suggest that the primary magma was derived from partial melting of Neoproterozoic to Phanerozoic newly accreted lower crust.According to the geochemical data and regional geological investigations,the Early Carboniferous granodiorites formed in an island arc setting linked to the subduction of the Paleo-Asian Oceanic Plate beneath the Xing'an Terrane.This also implies that the Xing'an and Songliao terranes have not amalgamated before the Early Carboniferous.

Zircon U-Pb geochronology and geochemistry of Early Cretaceous granodiorite porphyries in Hutouya,western Shandong and their implications for petrogenesis

Zircon LA-ICP-MS U-Pb age and whole-rock geochemistry data are presented for the Hutouya grano-diorite porphyries in Mengyin, western Shandong, to restrict its petrogenesis. The analyzed zircons exhibit os-cillatory growth zoning and core-rim textures in the cathodoluminescence images and have high Th/U ratios （0.04-1.66）,indicating its magmatic origin. The youngest group of magmatic zircon yields weighted mean 206Pb/238U age of 132 ±2 Ma, which represents the forming age of the granodiorite porphyries, i. e., the Early Cretaceous. The oldest group of magmatic zircon 207Pb/206Pb ages ranges from 2 398 Ma to 2 370 Ma, yielding a weighted mean age of 2 389 ±23 Ma,suggesting that the basement of the North China Craton should exist in the research area. Geochemically, the samples are characterized by high Si02（70. 38% and 64. 87% ） , low MgO （0.60% and 1. 53% ） and Mg# values （42. 92 and 50. 42）. Moreover, they show enrichment of light rare earth elements and large ion lithophile elements （e. g. Rb, Ba and K） , depletion of heavy rare earth ele-ments and high field strength elements （e. g. Nb and Ta） , positive anomaly of Pb, and negative anomaly of Ti. These results, together with previously published data, indicate that the Hutouya granodiorite porphyries were derived from partial melting of a delaminated lower continental crust and subsequent interaction with the mantle peridotites. They are consistent with the period of lithospheric thinning beneath the eastern North China Craton and may be formed in an extensional tectonic environment.

Early Cretaceous precious fossil-bearing beds in Weijialing—Yaolugou of Jianchang Basin,western Liaoning

The Jianchang Basin is one of the main localities of the precious fossils of Jehol Biota in western Liaoning.The fossil-bearing horizons are mainly in the Yixian-and Jiufotang formations.In the Weijialing--Yaolugou of southwest Jianchang Basin,many precious fossils have been found at Luojiagou Bed of the 2nd Member of the Yixian Formation and at Xidian Bed of the 1st member of the Jiufotang Formation.The geologic setting,sedimentary environment and paleogeography of the precious fossil-bearing beds were also studied.

Petrogenesis of Early Cretaceous riebeckite granophyres in southern Da Hinggan Mts.

This Aliwula area in paper reports lithologic features, K-Ar age and geochemical data of riebeckite granophyres from the southern Da Hinggan Mts., aiming to reveal the petrogenesis of riebeckite granophyres. K- Ar age of riebeckite granophyres is 126± 2 Ma, implying that the riebeckite granophyres formed in the Early Cretaceous. The granophyres are rich in riebeckites and with a lot of melt-fluid inclusion in its quartz pheno- crysts. The granophyres are characterized by extensive enrichment in Si02, FeO, and （Na20 ＋ K20） and de- pletion in MgO and CaO, strong negative Eu anomalies and strong positive Ce anomalies. Additionally, the rie- beckite granophyres not only have high total REE contents and display enrichment of HFSEs （for example Zr, Hf, Nb, Ta）, but also are strong in depletion of LILEs （ e. g. Ba, Sr） as well as high Ga/A1 ratios. Primitive mantle-normalized REE pattern significantly displays REE M-W tetrad effect. REEs fractionate evidently and highly enrich in LREE, but are uneven distribution in the rocks. Taken together, we conclude that the riebeck- ite granophyres are similar to typical A-type granite, which could be derived from stretching environments in the Early Cretaceous. The granophyres originated from residual melt which underwent highly differentiation process, and were formed in magmatic-hydrothemal transition stage at last.

New speices of Late Mesozoic wood fossils from southeastern Mongolia

Three new species of fossil woods are reported from the Upper,Jurassic to Lower Cretaceous in southeastern Mongolia, including Protaxodioxylon mongolense sp. nov. Circoporoxylon mongolen.;e sp. nov. Protocircoporoylon mongolense sp. nov. The anatomical characters of three new species are described in detail.

The first descendants of Homo erectus recognized from China

An indisputable fact is that human beings originated from Africa,where a nearly complete,but severely deformed fossil human cranium dating back about 7 million years was discovered and named as Sahelanthropus tchadensis,which is the oldest member of Family Hominidae in the world.Homo erectus was the first ancient human to move out of Africa and spread to Asia and Europe.Homo rhodesiensis was found from Africa,and Homo heidelbergensis was found from Europe.The fossils of Homo sapiens dating back about 300,000 years were found in Africa and considered to be the oldest fossil record of Homo sapiens.However,only some fossils of Homo erectus and Late Homo sapiens had been found in East Asia by that point,but Homo heidelbergensis or related human fossils had not been found in East Asia.According to the distribution of human fossils in the world at that time,some scholars suggested that Homo heidelbergensis was not only a descendant of African Homo erectus,but also the common ancestor of Homo sapiens,Homo neanderthalensis and Denisovans,leading to the formulation of the single African origin hypothesis of human beings.Clearly,the hypothesis is based largely on the assumption that Homo erectus in East Asia left no descendants.That is why any new human fossils found in China or East Asia would challenge the hypothesis.The discovery of Homo longi is a case in point.At that time,many scholars questioned the original location of the Harbin cranium,and even suggested that it came from the Middle East or Europe.Recently,we re-examined two Early Pleistocene human skulls(EV9001 and EV9002)from Yunxian County,Hubei Province,the age of which is approximately 0.96 to 1.1 million years.The two fossil human skulls were named as Homo erectus yunxianensis by Li Tianyuan and others in 1991.The cranium of EV9001 is marked by developing no sagittal ridge on the cranial roof and developing 16 teeth on the maxilla.The cranium of EV9002 is characterized by developing no sagittal ridge on the cranial roof and 15 teeth on the maxilla(the right third molar disappeared,the left third molar became small).It is clear that the two fossil human skulls were at a critical appearance time and a critical period of Pleistocene human evolution.We believe that the two fossil human skulls unearthed in Yunxian County,Hubei Province represent not only the common ancestor of the longi lineage and the sapiens lineage,but also the direct evidence of the first descendants of Homo erectus in East Asia.

Zircon SHRIMP U-Pb age, geochemical, Sr-Nd isotopic, and in-situ Hf isotopic data of the Late Carboniferous-Early Permian plutons in the northern margin of the North China Craton

The main rock types of the Boluonuo and Daguangding plutons are diorite, quartz diorite, tonalite, granodiorite, and subordi- nate plagioclase-bearing hornblendite and hornblende gabbro. Zircon SHRIMP U-Pb dating for a quartz diorite of the Boluo- nuo pluton suggests that the pluton was emplaced at about 296 ± 4 Ma. Plagioclase-bearing hornblendites show typical cumu- lative textures, which, in combination with their convex-upward REE patterns and the large variation of compatible elements such as Co, V and Sc, suggests that these hornblendites formed through accumulation of hornblende during magma evolution. Microgranular mafic enclaves （MMEs） are common in the Boluonuo and Daguangding intermediate to felsic plutons. Many plagioclase grains show compositional and textural disequilibrium, with calcium-rich cores （An46-50） mantled abruptly by sodium-rich plagioclase （An26-33）. Whole-rock samples of the plutons are characterized by quite negative εNd（t） values （-16.5 to -11.8） and εNt（t） values （-22.5 to -16.8）, and the εNd（t） values are negatively correlated with silica contents. All these fea- tures suggest that the intermediate to felsic plutons formed through magma mixing of enriched mantle-derived, evolved basal- tic magma with granitic, crustal melts, followed by fractional crystallization of mainly hornblende and small amounts of py- roxene, apatite and zircon. The hornblende-dominated fractionation contributed significantly to the adakite-like features of the intermediate to felsic plutons, like the high Sr and Sr/Y ratios and low Yb abundance. In addition, the Boluonuo and Daguang- ding plutons are highly enriched in LILEs （e.g., Ba and Sr）, but depleted in HFSEs （e.g., Nb, Zr and Ti）, which is typical of arc magmas. Therefore, the formation of Boluonuo and Daguangding plutons was probably related to the subduction of the Paleo-Asian oceanic slab beneath the North China Craton in the Paleozoic.

Early Cretaceous uplift history of the Dabie orogenic belt: Evidence from pluton emplacement depths

The North Dabie complex unit （NDC） is a widely exposed petro-tectonic unit. To understand post-orogenic uplift history and mechanism of the Dabie orogenic belt, many samples of granite, granodiorite, diorite, and alkali feldspar granite with precise zircon U-Pb ages were collected for electron microprobe analysis of hornblende. Emplacement pressure values were then cal- culated by using an Al-in-hornblende geobarometer. The result shows that total A1 （A1T） values in hornblende range from 1.17 to 1.97 p.f.u., XFe（=Fe/（Fe＋Mg）） from 0.4 to 0.65, and corresponding pressure values from 256.8 to 676.2 MPa for A1T greater than 1.17. It is suggested that although the main mechanism for the uplift is tectonic extension, inhomogeneous uplift related to the pluton emplacement is also important during post-orogenic evolution of the Dabie orogenic belt. Emplacement depth dis- tribution of the plutons shows that uplift in the NDC is affected by horst-graben structures since 120 Ma.

Modification of the lithospheric mantle by melt derived from recycled continental crust evidenced by wehrlite xenoliths in Early Cretaceous high-Mg diorites from western Shandong, China

This paper reports petrographic, mineral chemical, olivine oxygen isotopic, and whole-rock geochemical data for wehrlite xenoliths from the Early Cretaceous Tietonggou high-Mg diorites in western Shandong Province, in the eastern part of the North China Craton (NCC), and describes the origin of these wehrlites and the processes that affected the deep lithospheric mantle in this area.Wehrlite xenoliths are rounded and vary in size between 3 cm × 4 cm 5 cm and 3 cm 2 cm 1 cm.Olivine within these xenoliths occurs as an isolated residual phase within clinopyroxene, has Fo contents between 89 and 91, and contains between 1414 and 3629 ppm Ni, similar to the values of olivine from peridotite xenoliths in the Cenozoic basalts of eastern China, but lower than the values of olivine from harzburgite xenoliths in the Early Cretaceous high-Mg diorites in western Shandong.In situ oxygen isotope analysis yielded 18 O values of olivine from (6.03±0.33)‰ to (6.82±0.35)‰, averaging (6.5±0.4)‰; this is higher than typical mantle-derived olivine ((5.2±0.3)‰).Compared with clinopyroxenes from peridotite xenoliths in the Late Cretaceous and Cenozoic basalts, clinopyroxenes in the wehrlites contain relatively low concentrations of Na 2 O, TiO 2 , and Al 2 O 3 , high concentrations of CaO, and higher Mg # (91.2-94.1) and Ti/Eu ratios (2082-2845), being similar in composition to clinopyroxenes within harzburgite xenoliths in the Early Cretaceous high-Mg diorites.Clinopyroxenes from wehrlite xenoliths are characterized by low total REE abundance, enrichment in light REEs, and depletion in high field strength elements such as Nb, Ta, Zr, and Hf.Moreover, the 87 Sr/ 86 Sr, 143 Nd/ 144 Nd, and 187 Os/ 188 Os (125 Ma) ratios of these wehrlites vary from 0.70596 to 0.70737, 0.512181 to 0.512416, and 0.12661 to 0.57650, respectively.These data suggest that these wehrlite xenoliths were formed by modification of the lithospheric mantle by melts derived from recycled continental crust.

Yuzhou Flora——A hidden gem of the Middle and Late Cathaysian Flora

The Yuzhou Flora of the southern North China Platform possesses the typical regional features of the Middle and Late Cathaysian Flora.For a long time during the Permian,this area was located on shoreline marine tidal flats and deltas at low latitudes with a warm and humid climate.Consequently,many successive layers with abundant well-preserved plant fossils and a complete evolutionary sequence were developed.This is a unique and ideal place to study the Middle and Late Cathaysian Flora.We have recognized 111 genera and 307 species from this flora.The rapid morphological evolution and uninterrupted stratigraphic succession of Lobatannularia(Sphenophytes) make this group one of the bases for biostratigraphic divisions of the Permian System of the North China Platform.Ninety percent of Pteridophytes belong to the order Marattiales,which are well developed during the early and middle stages of the Yuzhou Flora but experience a sudden decline during the late stage.Ancient Pteridospermatophytes only flourished during the Middle Permian whereas advanced Peltaspermales are extremely well developed at the end of the early Late Permian.Among them Shenzhouphyllum is one of characteristic elements in the late stage of the Yuzhou Flora.The Cycadophytes evolved relatively early in this area and they differentiated and proliferated during the late Middle to early Late Permian.The number of species of Ginkgophytes is small but this group is extremely abundant,especially in the early Late Permian.The Gigantopteridales(preangiosperms) is a very important and unique group in the Yuzhou Flora.Based upon their venation and leaf architecture,this group can be divided into three evolutionary stages,i.e.,appearance and differentiation,first flourishing,and second flourishing and sudden disappearance,which form the basis for biostratigraphic division and correlation of the Permian System of the North China Platform.Based upon the evolutionary trend of venation pattern and leaf architecture,we propose some taxonomic changes at the generic level.The Yuzhou Flora emerged at the middle Early Permian(Zisongian) and suddenly disappeared at the early Late Permian(Wujiapingian).It is later replaced by the Euro-American Zechstein flora in the late Late Permian.The Yuzhou Flora is divided into three(early,middle and late) stages based upon the cyclic development of its plant groups.Five fossil plant assemblage zones are recognized from the Yuzhou Flora based upon the succession of each group and their combined characters in different layers.

Opening of an early Paleozoic limited oceanic basin in the northern Altyn area: Constraints from plagiogranites in the Hongliugou-Lapeiquan ophiolitic mélange

This paper reports petrological and geochemical features and zircon U-Pb age of plagiogranite from the Hongliugou-Lapeiquan ophiolitic melange belt in the northern Altyn Tagh. The zircon U-Pb dating results yield a mean ^238U/^206pb age of 512.1 ± 1.5 Ma, representing an emplacement time of the plagiogranites in the Middle Cambrian. The plagiogranites are interpreted to have derived from anatexis of hydrated amphibolites by ductile shearing during transports of the oceanic crust. Thus it is believed that the formation age of such type of plagiogranite was coeval to or slightly younger than the spreading of the Hongliugou-Lapeiquan limited oceanic basin. The new results from the plagiogranites suggest that an oceanic basin existed in the northern Altyn area during the Middle Cambrian.

Fenxiang biota:a new Early Ordovician shallow-water fauna with soft-part preservation from China

Our perception of biodiversity in the geological past is incomplete and biased because most organisms did not have mineralized skeletons and therefore had little chance of fossilization. This especially refers to shallow- water marine environments, rarely represented by localities with exceptional preservation of fossil material （known as taphonomic windows or Konservat-Lagerstaitten）. Such extraordinary “windows” may markedly broaden our knowledge of biodiversity of the past. Here, we show a review of the invertebrate fossils from recently discovered locality in the Lower Ordovician Fenxiang Formation of Hubei Province in southern China revealing exceptional preservation of soft tissues. The fauna, generally of shal- low-water aspect, contains linguloid brachiopods with a remarkably preserved pedicle, the oldest traces of nema- tode life activities, the oldest reliable record of hydroids, the first fossil antipatharian corals, a pyritized colonial organism of unknown affinity, supposed arthropod ap- pendages, probable phosphatized scalidophoran worm embryo and other fossils. Our discovery supports the opinion that the famous soft-bodied preservation of Bur- gess Shale- or Chengjiang-type did not vanish from the fossil record in post-Cambrian times. The new finding represents a prelude to the Great Ordovician Biodiversifi- cation Event and provides evidence for calibration of molecular clock of several invertebrate lineages.

New fossils of the Early Pleistocene Equus huanghoensis(Equidae,Perissodactyla)from Nihewan in Hebei Province of China

This paper describes new fossils of Equus huanghoensis from an Early Pleistocene bed in Nihewan, Hebei Province, which confirms the classification of E. huanghoensis by Chinese researchers. The new fossils include a relatively complete male skull and mandible with all upper and lower dentition, a broken female skull with fragment of mandible and a broken Mc III of Equus sp. The fossils were collected from the Yangshuizhan site of Nihewan. The age of the formation is about 1.6 Ma. The new materials verify some classification characteristics based on teeth published in previous descriptions. These characteristics include large teeth size, short protocone, and tilted protoloph and metaloph. We have added to these characteristics of large skull size, a developed protuberantia supramagna, pentagonal nuchal side, weak Pli cabaline, simple enamel plications; a series of new characteristics strikingly different from the other Equus horses. The broken Mc III is similar to Equus qingyangensis from Qingyang, Gansu.